There just aren't a lot of comps.  I dealt with one a few years ago where I personally was aware of several comps that were superior to the comps the appraiser used.  The appraisal was way under-value.  Unfortunately, if your state is a non-reporting state, I don't know if you can get the info.  I got around my issue by hiring a different appraiser.  But I had the advantage of going around a typical bank for my lending.  I don't think a bank would have accepted my 2nd appraisal.  I know they wouldn't have.